and stuck it in the trunk, I powered it with a 1000 watt amp, and with the top up, i had tons of bass, as soon as i lowered the top, I had none! I have since removed the sub and gave up on bass in that car..
If you could relocate the pump I think you could build a box right behind the seat?
I think the best way to do it would simply be to remove the rear seat and build a box into the space where the seat bottom was before. That's what I planning on doing sometime in the semi-near (read: next year or so) future. I suppose if you really value your back seat that's not a good option, but 94-95 vert rear seats are a joke anyway so...